Resolves Negative Subarray Task

src/main/java/eu/ztsh/training/hackerrank/datastructures/subarray/Solution.java

@@ -0,0 +1,30 @@
+package eu.ztsh.training.hackerrank.datastructures.subarray;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Arrays;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.IntStream;
+
+/**
+ * Java Subarray task.
+ * source: https://www.hackerrank.com/challenges/java-negative-subarray/problem
+ */
+public class Solution {
+
+    public static void main(String[] args) throws IOException {
+        var reader = new BufferedReader(new InputStreamReader(System.in));
+        var n = Integer.parseInt(reader.readLine());
+        var array = Arrays.stream(reader.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
+        var counter = new AtomicInteger(0);
+        IntStream.range(0, n).forEach(begin -> IntStream.range(begin, n + 1)
+                .forEach(end -> {
+                    if (Arrays.stream(array, begin, end).sum() < 0) {
+                        counter.incrementAndGet();
+                    }
+                }));
+        System.out.println(counter.get());
+    }
+
+}

src/test/java/eu/ztsh/training/hackerrank/datastructures/subarray/SolutionTest.java

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+package eu.ztsh.training.hackerrank.datastructures.subarray;
+
+import java.util.List;
+import eu.ztsh.training.hackerrank.HackerRankTest;
+import eu.ztsh.training.hackerrank.SolutionClassDescription;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DisplayName("HackerRank challenges: Java Subarray")
+class SolutionTest extends HackerRankTest {
+
+    @Test
+    public void testCase0() {
+        simpleAssert(
+                List.of("5", "1 -2 4 -5 1"),
+                List.of("9")
+        );
+    }
+
+
+    @Override
+    protected SolutionClassDescription getSolutionClassDescription() {
+        return new SolutionClassDescription(Solution.class);
+    }
+
+}